Swelling of the limbs

Introduction The clinical manifestations of limb lymphedema are persistent, progressive swelling of unilateral or bilateral limbs. The edema is depressed after the early pressing of the skin, also known as depressed edema. At this time, if the limb is continuously raised, the edema can be alleviated or subsided. If it is not treated in time, the condition will gradually progress, and the skin may become rough and hard and lumpy, and the elasticity will weaken to disappear. The pits of the depressions were also less pronounced as they weakened.

Cause

Lymphedema is a general term for a group of clinical signs or symptoms of systemic disease manifestations. The multi-source of the etiology and the complexity of the pathogenesis determine that it is difficult to classify it into simple categories. In the domestic professional books, lymphatic edema is not a good solution to the classification problem, and even congenital or acquired lymphedema. Confused with infectious lymphedema, etc., resulting in unclear limb lymphedema can be divided into two major categories of primary lymphedema and secondary lymphedema. Then, further classification according to the specific cause. It is worth mentioning that in many patients with lymphatic edema in the clinic, congenital lymphatic development defects can be combined with acquired trauma or infection factors to promote lymphedema.

Primary lymphedema

(1) Congenital lymphedema: A family history of congenital lymphedema, known as Nonne-Milroy disease, is characterized by lymphedema at birth. These patients account for 10% to 25% of all cases of primary lymphedema; and more common in women, female cases are more than twice as many as males; the lower extremities are more than the upper limbs, and the incidence ratio of upper and lower limbs is 1:3. Except for the extremities, the external genitalia, small intestine, and lung can be involved; and the molecular biological basis of developmental disorders related to congenital malformations in other parts is unknown, and the mechanism of lymphatic stasis is lack of in-depth discussion.

(2) Congenital lymphatic hyperplasia: This type of lymphedema is usually diagnosed when the child is 5 to 10 years old, but the history of the disease often shows mild edema after birth. The cause of lymphatic reflux stasis may be obstruction of the chyle pool, but there is still no objective basis. The clinical manifestations are swelling of the entire lower limb or bilateral lower extremities, but few concurrent infections. It differs from other types of lymphedema in that the subcutaneous lymphatic vessels are thickened and increased in number. These lymphatic vessels are distorted and have valve insufficiency. Ruminal reflux is common. Histological examination revealed thickening of the enlarged lymphatic muscle layer.

(3) Early onset and delayed lymphedema: These cases account for 80% of all primary lymphedema. Early onset lymphedema is more common in women, with an onset age of 20 to 30 years; delayed lymphedema occurs after 35 years of age. Edema initially occurs around the instep and ankle joints, and approximately 70% of patients have edema in the unilateral lower extremities. Lymphedema develops throughout the calf over several months or years, and edema rises to the thigh but is rare. Usually, such lymphedema tends to progress slowly after a few years of onset. About 30% of the contralateral limbs are involved after several years of edema in the primary limb. Such patients are rarely associated with acute episodes of dermatitis and lymphangitis. Histological examination showed that thickening of the intima of the lymphatic vessels and draining lymph nodes, collagen deposition under the intima, and muscle fiber degeneration suggest inflammatory pathological changes. There is no difference in the nature of early onset lymphedema and delayed lymphedema except for the onset time.

2. The causes of secondary lymphedema caused by secondary lymphedema can be summarized as follows:

(1) Traumatic or injurious: The cause includes iatrogenic lymph node biopsy and blockade of lymphatic drainage pathway after resection. Clinically common lymphedema of the limb caused by groin and axillary lymph node dissection. Any type of traumatic factors, including burns, especially in the bilateral axillary and groin areas, and extensive scar formation can lead to limb lymphatic drainage disorders and induce lymphedema.

(2) Infection or inflammation: Infection and inflammation are important factors that cause lymphatic morphology and dysfunction. Long-term chronic chest eczema, athlete's foot and its associated bacterial infection can easily lead to skin laceration. Streptococcus and staphylococcus invade the limb through the crack. If not treated properly, it can cause recurrent episodes of lymphangitis, high fever and limb swelling. Finally, lymphatic drainage is decompensated to cause limb lymphedema.

(3) Filaria Infectivity: Filariasis is a nematode infection. Before the 1950s, the epidemic lymphatic system in China, especially in the south of the Yangtze River, was one of the important invasive sites of filarial infection. Although filariasis has been eliminated in China, there are still many patients with lymphedema caused by filamentous infection.

(4) malignant tumor and lymphedema after radiotherapy: radical mastectomy can cause upper limb lymphedema; pelvic tumor, penile cancer and other surgical resection, local lymph node dissection or postoperative radiotherapy, are easy to concurrent with lower extremity lymphedema. Hodgkin's disease can also cause lymphedema in the limbs because lymphoma cells invade the lymphatics and lymph nodes, causing blockage or destruction of the lymphatic pathway.

It is not uncommon for lymphosarcoma and AIDS to develop lymphatic edema due to their major invasion of the lymphatic system. Tumor-induced lymphedema is characterized by edema that originates at the proximal end of the limb and then spreads distally. Lymphatic imaging can show the obstruction site, which helps the clinical diagnosis of lymphedema caused by tumor often have a clear history, such as surgery, radiotherapy history, but should not ignore the early lymphedema of some tumors, and delay the most cancer treatment Good time. The Institute of Rehabilitation Surgery of the Ninth People's Hospital affiliated to Shanghai Second Medical University, the cause of early diagnosis and treatment of 1043 cases of limb lymphedema was as follows: 112 cases of primary lymphedema (10.74%); 931 cases of secondary lymphedema (89.26) %), of which 487 cases (46.69%) were 287 cases (27.52%), 78 cases (7.48%) were traumatic, 53 cases (5.08%) after operation, and 26 cases (2.49%).

Pathogenesis of limb lymphedema

The basic factor of lymphedema is that the initial cause of lymphatic retention due to lymphatic retention is the obstruction of the lymphatic return channel. Some scholars call lymphedema as "low-output failure" to distinguish tissue edema caused by lymphatic fluid accumulation and increased lymphatic load overload, such as hypoproteinemia, venous embolism, and lower extremity arteriovenous fistula. The latter is also known as "high-output failure" because the initial cause of such edema is outside the lymphatic system, and the relative lack of lymphatic output is the result of elevated venous pressure and excessive exudation of water and protein. Edema does not belong to lymphedema.

From an anatomical point of view, lymphatic drainage disorders can occur in all levels of lymphatic pathways, such as the initial lymphatic vessels, the dermal lymphatic network, the collecting lymphatic vessels, lymph nodes, chyle pools, and thoracic ducts. Due to the different sites of lymphatic obstruction, the pathophysiological changes of lymphedema caused by different lymphaspasm are different. For example, the pathophysiological changes in the pelvic large lymphatic vessels are completely different from the initial lymphatic vessel occlusion. In addition, different pathogenic factors, such as trauma, The pathogenesis of lymphatic vessels caused by infection with radiation, etc. is also different. The cause of primary lymphedema such as Nonne-Milroy disease is unclear.

The pathological process of chronic lymphedema is divided into three stages: the edema stage of fat hyperplasia and the stage of fibrosis. In the early stage of the disease, the lymphatic reflux is blocked, and the pressure in the lymphatic vessels is increased, causing the lymphatic vessels to expand and distort. The gradual loss of valve function, lymphatic reflux, affects the ability of the capillary lymphatic vessels to absorb interstitial fluid and macromolecular substances, resulting in the accumulation of body fluids and proteins in the interstitial space. The swelling of the lower extremity lymphedema firstly starts from the lower part of the ankle and gradually expands from the bottom to the top. The limbs are evenly thickened, and the lower part of the ankle and the lower leg is 1/3. At this time, the skin is smooth and soft, and there is depression edema during acupressure. After raising the affected limb and rest in bed, the swelling can be obviously subsided, and this stage belongs to the stage of lymphedema.

Edema persists under the stimulation of lipid components. Macrophages and fat cells phagocytose lipid components in the lymph, subcutaneous fat tissue proliferates, limb toughness increases, skin keratinization is not obvious, edema transitions to non-depressed, lymphatic Edema enters the stage of fat proliferation, and tissue swelling at this stage mainly includes stagnant lymph and hyperplastic adipose tissue.

Under the long-term stimulation of high protein components, the skin and subcutaneous tissue produce a large amount of fibrous tissue, and the lymphatic wall is gradually thickened and fibrotic, so that the tissue fluid is more difficult to enter the lymphatic vessels, and the high protein edema is further aggravated. High protein edema fluid is a good medium for bacteria and other microorganisms. It is easy to induce infection in local areas. Recurrent erysipelas infection increases local tissue fibrosis, aggravates lymphatic obstruction, and forms a vicious circle called fibroproliferative phase. Clinically, the skin is gradually thickened, the surface is excessively keratinized, rough and hard as the skin, and even the limbs of the sacral hyperplasia, lymphatic or ulcers are extremely thickened to form a typical elephantiasis.

an examination

Related inspection

Continuous plasma protamine dilution test plasma tissue plasminogen detection plasma tissue plasminogen activator inhibitor antigen detection white blood cell count (WBC) plasma protein C antigen

Clinically, lymphedema is generally classified into four stages according to the degree of limb edema and secondary lesions.

Stage I lymphedema health search: limbs have mild, moderate swelling, no limb fibrosis or only mild fibrosis.

Stage II lymphedema: Local edema and fibrosis are obviously thickened, but the circumference of the cupping network on both sides is less than 5 cm.

Stage III lymphedema: local edema and fibrosis were obvious, the affected limbs were significantly thickened, and the circumference of both limbs was more than 5 cm.

Stage IV lymphedema: severe advanced edema skin tissue is extremely fibrotic, often accompanied by severe limb keratosis and spine formation, the entire limb is abnormally thickened, shaped like elephant legs, also known as elephantiasis.

According to medical history and clinical manifestations, the diagnosis of lymphedema is generally not difficult. Different causes and clinical manifestations may vary slightly, but they also have in common:

1 soft depressed edema that begins to increase from the ankle and lasts for several months without any other symptoms.

2 The increase in limb diameter increases the weight of the limb, and the patient often complains about limb fatigue.

3 As the subcutaneous fibrosis progresses, the limbs become hard and develop into non-recessed edema, and the skin becomes hard and keratinized.

Laboratory inspection:

Includes a differential white blood cell count. When searching for eosinophils in filariasis, the peripheral blood smear can be found in Wu Ceban. Plasma proteins, total protein electrolytes, renal function tests, liver function tests, urinalysis, etc. can help to rule out other causes of limb edema.

Other auxiliary inspections:

1. Diagnostic puncture: Diagnostic puncture can help identify deep hemangioma and venous edema. The examination only requires a syringe and a puncture needle. The method is simple, but the lesion and function of the lymphatic vessel cannot be understood. The protein content of lymphedema fluid is usually very high, generally in the range of 10 ~ 55g / L (1.0 ~ 5.5g / dl) and venous stasis, cardiogenic edema and hypoproteinemia edema tissue protein content of 1 ~ 9g / L (0.1 ~0.9g/dl).

2. Lymphangiography: Lymphangiography is a method of injecting contrast agent directly or indirectly into the lymphatic vessels to develop a radiograph, and to observe the morphology and reflux function of lymphatic vessels. It is divided into direct lymphangiography and indirect lymphangiography. Lymphangiography Because the contrast agent remains in the lymphatic vessels, combined with lymphatic drainage disorder, the contrast agent causes secondary damage to the lymphatic vessels. Therefore, most people now do not advocate lymphangiography.

(1) Direct lymphangiography: firstly use reactive dyes such as 4% methylene blue 2.5%-11% acid lake blue, 0.5% to 3% Evans blue to be injected under the nail, and then in the guide injection The skin was cut at 5 cm near the site, and the blue-stained lymphatic vessels under the dermis were found. Under the operating microscope or magnifying glass, a ligation needle with a diameter of 0.3 to 0.35 mm was used to puncture the lymphatic vessels and the iodine agent was slowly injected. Contrast agent spillover or lymphatic vessel stimulation may cause inflammatory reaction, routine application of antibiotics, and raise the affected limb, pay attention to rest.

(2) Indirect lymphangiography: an imaging method in which a contrast agent is injected into the body and absorbed by the lymphatic vessels. The contrast drug developed in the early stage is highly irritating, the drug absorption is unstable, the development is irregular, and it is confused with the vascular image, which has not been widely applied in clinical practice. In 1988, the advent of a new generation of contrast agent, Isola, enabled clinical use of indirect lymphangiography.

The contrast method is to inject the contrast agent into the suboccipital space. After 2 to 3 minutes, the lymphatic vessels are filled, the contrast agent spreads to the heart, and the lymphatic vessels are gradually developed. About 10 minutes after the injection, the inguinal lymph nodes have been developed and observed.

Normal lymphatic angiography can see a small tube of 0.5 ~ 1mm, the caliber is the same, the corrugation is smooth, and the spindle shape is 1cm apart. The lesions of the lymphatic valve position can be presented regardless of primary or secondary lymphedema. The following performance:

1 The number of lymphatic vessels is reduced, or not developed, or only the distal lymphatic vessels are seen, which may be congenital lymphangiogenesis or secondary occlusion of the lymphatic vessels, which cannot be developed.

2 lymphatic hyperplasia, distortion, dilatation, valve failure, intradermal regurgitation, or lymphatic vessel interruption. Mainly for secondary lymphedema, caused by proximal lymphatic blockage, also seen in a small number of primary lymphedema.

3. Radionuclide lymphography: After the radioactive tracer of macromolecule is injected into the interstitial space, it enters the lymphatic vessel and is almost completely removed by the lymphatic system. The imaging device can display the pathway and distribution of lymphatic reflux and lymphatic reflux. The dynamics of the change. A variety of nuclides have been used clinically, and the most commonly used is 99mTc-Dextran. After injecting nuclide between the toes (finger), static image scanning was performed at 1/2h, 1h, 2h and 3h respectively.

Radionuclide lymphography can clearly show the lymph nodes and lymph nodes of the limbs, and can show lymphatic reflux. Once the radionuclide enters the blood circulation, it is quickly taken up by organs such as the liver, spleen and lungs, affecting the mediastinal lymph nodes of the upper abdomen. The radionuclide lymphography method is safe, simple, reproducible, and painless. It can be used for comparison before and after treatment. It is the most valuable diagnostic method for limb lymphedema.

Differential diagnosis

Limb lymphedema with its characteristic non-recessed edema and advanced tissue fibrosis caused by skin and subcutaneous tissue like skin-like changes, combined with lymphography and lymphatic imaging health search, clinical diagnosis is generally not difficult, but edema as a symptom And signs, a variety of diseases can be caused, involving a number of clinical departments, in the diagnosis of lymphedema should still be differentiated from a variety of diseases.

1. The bilateral limb edema should first be distinguished by lymphedema caused by accumulation of lymph with high protein content, or edema caused by accumulation of body fluid with low protein content such as cardiac hepatic, renal, dystrophic and other systemic edema. And localized venous or neurovascular edema. This can generally be identified by medical history, physical examination and laboratory tests.

2. Unilateral limb edema should be distinguished from venous disease. Limb edema caused by venous disease usually has characteristic skin atrophy and deep pigmentation and long-term venous stasis. It is easier to distinguish from lymphedema, and angiography is also an effective means to distinguish between venous and lymphedema. However, it should be noted that most of the limb swelling caused by late venous obstruction or poor reflux has a lymphatic drainage disorder, and the appearance of lymphatic drainage disorder will aggravate the venous reflux disorder. It should be taken seriously when handling.

3. Female patients should pay attention to the differentiation of fat edema when limb edema occurs. Fat edema is a rare disease that affects women. This fat metabolism disorder is characterized by diffuse, symmetrical, non-recessed subcutaneous tissue of the limb, but its lymphatic imaging shows no abnormalities in lymphatic and lymphatic drainage.

4. Some patients with lymphedema have a short history, and obvious limb swelling occurs in a short period of time. The possibility of pelvic tumor metastasis should be guarded. Such as cervical cancer, prostate cancer metastasis to the axillary lymph node obstruction of the limb lymphatics or compression of the iliac vein caused by more serious lymphedema of the lower extremities, should be noted in the diagnosis.

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